A Conservative member of the London assembly who insisted his expenses are "none of the public's business" has been forced to publish them today following pressure from Boris Johnson.

Brian Coleman, the Conservative assembly member for Barnet and Camden, riled Tory party colleagues by saying in a media interview yesterday that the general public was not "entitled to drool over our personal lives" as he defended his decision not to take part in the voluntary publication of his receipts for the past year.

Coleman said yesterday: "I'm from the Boris school of anarchist thinking. If somebody tells me to do something, I don't want to do it."

But Coleman, who was appointed chief of the fire and emergency planning authority by Johnson, the Conservative mayor, was forced into a humiliating climbdown after a senior member of the mayor's team made clear on the mayor's behalf his stance on openness and transparency within his administration.

A spokesman for the mayor told the Guardian today that Coleman "has happily agreed to put his expenses online and they will be up later today".

Coleman was the only one of the 25-strong elected London assembly to refuse to voluntarily publish his expenses, which went online on Monday night, following an assembly committee recommendation.

The move was suggested following the resignation of Boris Johnson's former deputy mayor, Ian Clement, over expenses claims he made that turned out to be wrong.

Coleman told the London Evening Standard yesterday that his expenses were "none of the public's business".

"They are not entitled to drool over our personal lives. I'm not going to help the mad, bad and the sad, the bloggers on the internet. I'm not pandering to mob rule. It undermines democracy to suggest that all MPs, all politicians are the spawn of Beelzebub."

Challenged on the fact that all but one of his Conservative assembly colleagues had incurred lower claims, Coleman reportedly said: "Politicians with lower expenses tend to be the politicians who do least work. Those with higher expenses are the ones who do most work."

Figures included in the Greater London authority's statement of accounts show Coleman spent £1,946 on taxi fares for assembly business in 2008-09. Coupled with the £1,784 cost of a travel card paid for by City Hall, this brings the total amount of expenses incurred by Coleman in his capacity as an assembly member over the last year to £3,730 – the third-highest bill after Johnson and his deputy mayor Richard Barnes.

In 2007-08, Coleman spent more than £8,000 in taxi fares – more than the other 24 members of the London assembly put together. The year before, he notched up over £10,000 in fares. Separate figures passed to the Guardian show Coleman also notched up a £275 taxi bill to attend the annual carol concert held by the London fire brigade at Westminster cathedral in his capacity as chair of the London fire and emergency planning authority last December. This came on top of a previously reported taxi ride to the lord mayor's banquet that cost the taxpayer £400.

Two weeks ago, it was reported that Johnson spent £4,698 on taxis as part of an overall claim for his first year in office of £8,170, casting doubt on his self-avowed attachment to use a bicycle to get around London.

Meanwhile Barnes, who is also the London assembly member for Ealing and Hillingdon, incurred £2,921 as part of a total expenses claim of £5,732.

A spokesman from the Conservative group office said Coleman was not prepared to comment.